But could Kim Jong Un, North Korea's new dictator, have purged even his own wife from his inner circle?

Speculation as to the fate of Ri Sol-ju, the petite former singer whom he married in 2009, is growing in the aftermath of the sudden death of Kim's uncle, Jang Sung Taek, whose execution for treason was announced by Pyongyang last Thursday.

The killing of a man regarded as a regime stalwart has demonstrated that even family members are not safe. Ms Ri, who regularly appeared by her husband's side, has not been seen since October.

As the Daily North Korean, a Pyongyang-watching newspaper based in the South, put it earlier this month: "Why Has Ri Been Gone for 48 Days?"

On Tuesday, video footage was released by North Korean media appearing to show the pair at a memorial service commemorating the second anniversary of the death of Kim Jong Il, from whom Kim took over as leader of the world's only hereditary communist republic. But many experts claim the pictures were from a previous service last summer.

"Comrade Ri Sol Ju", who is understood to be in her late 20s, first caught Kim's eye as a singer in the Unhasu Orchestra, one of several musical glamour troupes that serve as in house-bands -- and sometimes concubines.

Little more is known about her -- her name is thought to be a pseudonym -- although she is believed to harbour a ruthless streak herself.